For parts that slide while maintaining seal, such as gaskets each of which is integrated with a syringe plunger and forms a seal between the plunger and the barrel, elastic bodies (e.g. rubber) are used in great consideration of sealing properties. Such elastic bodies, however, have a slight problem in their sliding properties (see Patent Literature 1). Hence, a sliding property improver (e.g. silicone oil) is applied to the sliding surface, but it is pointed out that silicone oil can have a bad influence on recently marketed bio-preparations. On the other hand, a gasket to which a sliding property improver is not applied is poor in the sliding properties. Thus, the plunger cannot be pushed smoothly so that it pulsates upon administration, thereby causing problems such as inaccuracy in the injection amount and infliction of pain on patients.
In order to simultaneously satisfy such conflicting requirements, that is, the sealing properties and the sliding properties, one technique is proposed in which a self-lubricating PTFE film is applied (see Patent Literature 2). Such a film, however, is generally expensive and causes an increase in the production cost of processed products, and thus its application range is limited. Also, products covered with the PTFE film might not be reliable in the case that the products are used in applications in which sliding or the like motion is repeated and durability is thereby required. Another problem is that PTFE is vulnerable to radiation and thus it cannot be sterilized by radiation.
Furthermore, the parts may be used in applications requiring sliding properties in the presence of water. Specifically, water can be delivered without a loss by reducing the fluid resistance of the inner surface of a pre-filled syringe or the inner surface of a pipe or tube for delivering water (e.g. catheters), or by making its contact angle with water high or greatly low. Also, drainage of water on wet roads and of snow on snowy roads can be improved by reducing the fluid resistance of the groove surface of tires, or by making its contact angle with water high or greatly low. This results in enhanced grip and enhanced hydroplaning properties, leading to better safety. In addition, less sticking of wastes and dusts is expected as a result of reducing the sliding resistance of the sidewall surface of a tire or a wall of a building, or as a result of making its contact angle with water high.
Further advantageous effects can be expected, such as less pressure loss when water, an aqueous solution, or the like is delivered through a diaphragm such as a diaphragm pump or a diaphragm valve; easy sliding of skis or a snowboard by enhancing the sliding properties of the sliding surface thereof; better noticeability of a road sign or a signboard by enhancing the sliding properties thereof to allow snow to slide easily; reduction in water resistance or drag and less sticking of bacteria on the outer peripheries of a ship by reducing the sliding resistance of the outer peripheries or by making their contact angle with water high; and swimsuits with reduced water resistance or drag by improving the sliding properties of the thread surface thereof.